[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH 01/28] tcg: Add flags argument to bswap opcodes
|
From: |
Peter Maydell |
|
Subject: |
Re: [PATCH 01/28] tcg: Add flags argument to bswap opcodes |
|
Date: |
Mon, 21 Jun 2021 14:51:42 +0100 |
On Mon, 21 Jun 2021 at 14:41, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> On Mon, 14 Jun 2021 at 09:43, Richard Henderson
> <richard.henderson@linaro.org> wrote:
> >
> > This will eventually simplify front-end usage, and will allow
> > backends to unset TCG_TARGET_HAS_MEMORY_BSWAP without loss of
> > optimization.
> >
> > The argument is added during expansion, not currently exposed
> > to the front end translators. Non-zero values are not yet
> > supported by any backends.
>
> Here we say non-zero values are not yet supported by the backend...
Looking at the tcg/README docs, I think what you mean is that
at the moment all the backends assume/require that the caller passes
one of TCG_BSWAP_IZ or (TCG_BSWAP_IZ | TCG_BSWAP_OZ), since the
pre-flags implementation requires the top bytes to be zero and leaves
them that way. But then the parts of your patch that pass in a zero
flags word would be wrong...
-- PMM
- Re: [PATCH 03/28] tcg/aarch64: Support bswap flags, (continued)
- [PATCH 04/28] tcg/arm: Support bswap flags, Richard Henderson, 2021/06/14
- [PATCH 05/28] tcg/ppc: Split out tcg_out_ext{8,16,32}s, Richard Henderson, 2021/06/14
- [PATCH 01/28] tcg: Add flags argument to bswap opcodes, Richard Henderson, 2021/06/14
- Re: [PATCH 01/28] tcg: Add flags argument to bswap opcodes, Richard Henderson, 2021/06/21
[PATCH 02/28] tcg/i386: Support bswap flags, Richard Henderson, 2021/06/14
[PATCH 06/28] tcg/ppc: Split out tcg_out_sari{32,64}, Richard Henderson, 2021/06/14
[PATCH 08/28] tcg/ppc: Split out tcg_out_bswap32, Richard Henderson, 2021/06/14